Network model in the database with examples and characteristics.
What is the database network model?
When we want to design the database, there is a variety of database models. Relational, hierarchical and network models are famous models. You can read the tutorial about these topics here by clicking the model name. In this tutorial, we will explore the database network model.
The network database model is a model for modeling the entities in such a way that one child entity can have more than one parent entities.
Example of a network model
In this figure, we can see that the subject is the child class and student and degree are the parent classes.
So, the subject has two parent classes. STUDENT has one child and Degree class also have one child.
This kind of relationship among entities represents the network model.
Characteristics of the network model
There are many characteristics of the network model, some of these characteristics are mentioned below;
- The network model is better than a hierarchical model.
- Supports many to many relationships.
- Many parents can have many children.
- Many children can have many parents (as shown in the figure).
- Entities are represented as a connected network with each other.
- One child entity can have more than one parent entity. For example, in the figure, the Subject has two children. One child is a STUDENT and another one is Degree.
- Represented as a network and one child can have more than one parent. This model represents a complex structure.
- Entities can have multiple parent entities and lead to a complex structure.
- Not very flexible to reorganize the model.
- High performance
- Relationships among databases are done by programmers by using 3GL programs.
- Query facility is not available in the network model.
Hierarchical Database Model VS Network Database Model
|Hierarchical Database Model||Network Database Model|
|Relationship: One to many relationships||Relationship: Many to many relationships|
|More flexibility within the information due to the hierarchical position of the files.||Great flexibility among the information due to multiple relationships among the data files.|
|Difficult to access because there is the strictness of the owner to member connection.||Easily accessed due to linked information|
Advantages of the network model
- It is fast data access with a network model.
- The network model allows creating more complex and more strong queries as compared to the database with a hierarchical database model. A user can execute a variety of database queries when selecting the network model.
Disadvantages of a network model
- The network model is a very complex database model, so the user must be very familiar with the overall structure of the database.
- Updating inside this database is a quite difficult and boring task. We need the help of the application programs that is being used to navigate the data.
|Test Your Understandings|
1. Network model supports many to many relationships ? YES / NO
2. Network model is more complex than hierarchical model? YES / NO
3. Network model relationships are written in ………language?
(d) None of them